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Shawn Harrison
harrison at tbc.net
Wed Feb 9 10:28:45 EST 2005
Graham Dumpleton wrote [02/04/05 9:51 PM]: > > On 05/02/2005, at 1:27 AM, Shawn Harrison wrote: > > [...] > >> I do have a question about Vampire. I want to have a Python script >> >> /web/websitename/www/photos/index.py >> >> where I've appended /web to sys.path, so that >> >> websitename.www.photos.index >> >> is a module name. Okay. I want to publish photos with urls like >> >> http://websitename/photos/2004/10/01/137 >> >> Can Vampire send all requests for paths under /photos/ to the photos > > > Not knowing for sure what you are wanting to do, I am going to assume that > you want to wrap image files in a HTML page automatically. Yes, that's the idea, although I only gave photos as an example: What I really mean is this: * If my document root is /web/examplecom/www/, and * I have a request handler at /web/example/www/photos/index.py, and * the photos are in /web/example/www/photos/ * Vampire is the PythonHandler, and * req.uri is /photos/2004/10/01/137, then ? will the handler in /photos/index.py pick up the request? I've been using my own homebrewed handler to publish objects dynamically in this fashion (using req.path_info, etc.). But, it's not ideal. I am asking this basic question about Vampire because the answer with mod_python.publisher appears to be, no, it won't (which is why I made ye olde homebrewe a few months ago). The answer with Quixote is, yes it could if I set it up right. The answer for Vampire is not clear in its documentation. Based on the rest of your reply, I am inferring that Vampire can handle dynamic object publishing from a database or filesystem, but that the set up would have to be different from what I've been using. > Firstly, Vampire is structured so as to avoid altogether use of sys.path > and all the complications that can arise because of it. Thus, you would > not add "/web" to sys.path. Having '/web' in sys.path is fairly basic to the architecture that I've been developing. Every "web service" is a folder under /web, and each includes both request handlers and regular Python modules, including database access modules. I also want to be able to use Apache as one front end among many, not as the only one; so I need to be able to import modules in a more-or-less Python-native fashion. > Thus, to configure things, one would use: > > Options -Indexes -MultiViews > > SetHandler python-program > PythonHandler vampire > PythonPath 'sys.path' > PythonDebug On > > Indexes are turned off because we wouldn't want it, and MultiViews is > turned off because auto negotiation of file types screws with how > Vampire works. That makes sense. > PythonPath is set to "sys.path" in order to stop mod_python from > adding that directory into "sys.path" as we don't want that either. > This is so nothing tries to attempt to load any Python code files in > the document tree as Python modules using "import". > > Assuming that the "photos" directory is where the images actually > live, am going to change things around a little and rename "photos" > to "library". > [...] > Note that the reason I had to rename the directory containing the images is > that the way Apache resolves paths, it will give precedence to subdirectory > search matching and thus will not hand off control to Vampire properly if I > had "photos.py" handler and "photos" directory. I don't understand why this is so, but I also don't understand the innards of the Vampire. In my crufty homebrew handler, this kind of situation resolves to using the handler in /web/examplecom/www/photos/index.py. But I see that you achieve essentially the same results. There is something to be said for keeping the data files (which you put in /library) separate from the application code. > [...] > Hope this is of interest. This might actually be a good example for me of > showing off Vampire. Although, I could see it being extended further than > this simple bit of code to become a nice photo album viewer. Yes, it's an interesting example, and it provides a lot of information about how Vampire would deal with various usage scenarios. You should add some of these details to your documentation. > > Graham > > > # Now for the code. I enjoyed reading it. > > from mod_python import apache > > import os > import posixpath > > _PAGE = """ > <html> > <body> > <h1>Photo: %(name)s</h1> > <img src="%(url)s" /> > </body> > </html> > """ > > # Handler for virtual directory. > > def handler(req): > > # Determine stub of image file to view. > > if req.path_info == "": > return apache.HTTP_BAD_REQUEST > elif req.path_info == "/": > return apache.HTTP_BAD_REQUEST > > name = os.path.splitext(req.path_info[1:])[0] > > # Determine what type of image file it is. > > subdir = "library" > # subdir = "." # use this if wanting to make it "browse.py" in > "photos" subdir > > root = os.path.join(os.path.dirname(req.filename),subdir) > > path = None > extn = None > > allowed = [ ".jpg", ".gif" ] should be allowed = ['.jpg', '.png'] ;-) > > for suffix in allowed: > file = os.path.join(root,name) + suffix > > if os.path.exists(file): > path = file > extn = suffix > > if path == None: > return apache.HTTP_NOT_FOUND > > # Determine the URL to the actual image. > > baseurl = os.path.dirname(req.uri[:-len(req.path_info)]) > > url = posixpath.join(baseurl,subdir,name+extn) > > content = _PAGE % { "name": name, "url": url } > > # Return the rendered page content. > > req.content_type = "text/html" > req.send_http_header() > > req.write(content) > > return apache.OK Thanks again, -- ________________ harrison at tbc.net
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